Apparatus and method for administering humidified anesthetic gases



Oct. 3, 1967 A. GOODEN 3,345,047

APPARATUS AND METHOD FOR ADMINISTERING HUMIDIFIED ANESTHETIC GASES Filed Feb. 7, 1966 2 Sheets-Sheet 1 FIG.

4 l" INVENTOR.

AMM 4. 6000:

7 ArranvE/J A. L. GOODEN APPARATUS AND METHOD FOR ADMINISTERING HUMIDIFIED ANESTHETIC GASES Oct. 3, 1967 Filed Feb.

2 Sheets-Sheet 2 INVENTOR.

United States Patent 3,345,047 APPARATUS AND METHOD FOR ADMINISTER- IN G HUMIDIFIED ANESTHETIC GASES Alan L. Gooden, 1214 th Ave., Neptune, NJ. 07753 Filed Feb. 7, 1966, Ser. No. 532,817 8 Claims. (Cl. 261-90) The present invention relates to an apparatus and method for creating tiny droplets particularly applicable for humidifying explosive gas mixtures.

This application is a continuation-in-part of.Ser. No. 272,792, filed Apr. 12, 1963, now abandoned, by Alan L. Gooden for Method and Apparatus for Creating Tiny Droplets.

In the handling of explosive gas mixtures, such as anesthetic gas and oxygen, there is the ever-present danger of accidental explosion. Under the typical conditions in an operating room such an explosion is of extreme risk to the patient because the explosive gas mixture is present in the patients lungs. Moreover, this danger of explosion is increased greatly because of the very low humidity of the gas mixture.

In many instances the oxygen and anesthetic gas are fed as dry, compressed gases from high-pressure supply tanks, and these gases are released from the high-pressure tanks through pressure-reducing valves as the anesthetic mixture is used. The result is that these gases are very dry at the time when they are mixed together for administering to the patient. This very low humidity creates an environment within the gas mixture and along the walls of the surrounding chambers and passages which fosters the build-up of static electricalcharges. There are multitudes of safetyvprecautions which are taken in hospital operating rooms so as to guard against the accidental spark discharge of static electrical charges in or about the explosive gas mixture. However, the low humidity of this explosive gas mixture favors the buildup of static electrical charges because of the high resistive or insulating quality of the dry gases. Also, the dryness of the gas mixture continually robs the patients lungs of moisture content, and in a lengthy operation the patient often suffers from a significant loss of water from his body.

Among the many advantages of the present invention are those resulting from the fact that an explosive gas mixture may be humidified safely to a high relative humidity. For example, the apparatus described herein as illustrative of the present invention readily raises the humidity level above 60 percent and in most instances above 80 percent. Thus, advantageously, the conductivity of the gas mixture is raised by the high moisture content and by moisture on the walls of surrounding passages and chambers, so that static electrical charges cannot build up, and this hazard of explosion is substantially reduced. Moreover, the moisture content of the patients lungs and body are desirably preserved. In the illustrative ex amples disclosed herein the gas pressure itself is utilized as a source of power for actuating the humidification apparatus.

In this specification and in the accompanying drawings, are described and shown an embodiment of the invention for humidifying explosive gas mixtures, and various modifications thereof are indicated. It is to be understood however, that these are not intended to be exhaustive nor limiting of the invention, but on the contrary are given for purposes of illustration in order that others skilled in the art may fully understand the invention and the manner of applying the apparatus in practical use.

The various objects, aspects, and advantages of the present invention will be more fully understood from a consideration of the following specification in conjunction with the accompanying drawings, in which:

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FIG. 1 is an illustrative diagram of an anesthetic gas mixture system embodying the present invention;

t FIG. 2 is a perspective view of the humidifying appara- FIG. 3 is a cross-sectional view of the apparatus taken along the lines 33 of FIGS. 2 and 4;

FIG. 4 is a longitudinal section of the rotor chamber of the humidifying apparatus taken along the line 4-4 of FIG. 3; and

FIG. 5 illustrates the way in which a rapidly moving bristle driven by suitable motive means flicks numerous tiny droplets of moisture into the atmosphere for creating tiny breathable droplets.

The patient to be anesthetized is arranged so that his mouth and nose are beneath a face mask 2, shown in FIG. 1, which is connected by a hose 4 with a water separator 6. This separator 6 has an elongated cylindrical configuration with a drain 8 for water extending from the bottom for suitable disposal of the water, and the hose 4 extends from the upper end of this separator 6. The oxygen is supplied from a high-pressure tank 10 and a suitable anesthetic gas, for example, such as cyclopropane is supplied from a similar tank 12.

A shut-off valve 14 releases the oxygen gas from the tank 10 through a line 16 and through a pressure-regulation valve 18 and a supply line 20 to a small mixing chamber 22. Similarly, the anesthetic gas is released by a shut-off valve 24 and fed through a line 26 and a pressure-regulating valve 28 and a supply line 30 into the mixing chamber 22.

In order to humidity safely the explosive mixture of gases coming from the mixing chamber 22 and supplied through a hose 32, there is a humidifying device 34 having its output connected by a hose 35 with the water-separator 6. This separator allows any water droplets to drop out of the gas stream before the gas mixture reaches the face mask 2.

As-shown in FIG. 2, the humidifying device 34 includes a transparent tank or reservoir 36 having a vertical cylindrical side wall and a water-tight bottom, for example of glass. This reservoiris filled with water to a depth of several inches, with the water level being indicated at 38. The input hose 32 is attached to a vertical tube 40 which is secured to the cover 42 of the tank 36, and which extends down through this cover into the water so as to discharge the gas mixture into the water near the bottom of the tank 36. The gas bubbles up through the water into the collection space 44 beneath the cover In operation the gas mixture flows up from this collection space 44 through a duct 46 connected to a manifold 48 extending along beside a rotor casing 50. There are numerous openings 52 through the casing 50, and these openings are positioned along the length of the manifold 48 so as to connect the interior of the manifold with the interior of the casing 50 near the general region A. One of these openings 52 is seen in section in FIG. 3.

Within the rotor casing 50 is an elongated cylindrical hollow rotor 54 having its end 55 rotatably mounted on a bearing 56 connected to the end wall 57 of the casing. The output hose 35 is connected to an outlet port 58 in the other end wall 59 of the casing 50.

For purposes of humidifying the gas mixture as it passes through the openings 52 into the region A within the rotor casing 50, there are multitudes of fine flexible plastic bristles 60 projecting from the periphery of the rotor 54. Also projecting from the surface of the rotor among the bristles 60 are a plurality of flexible plastic vanes 62, each of which extends the full length of the rotor. These vanes 62 are uniformly spaced about the circumference of the rotor as seen in FIG. 3, and the rotor is eccentrically located in the space within the casing so as to provide a rotating propulsive force due to the gas pressure and flow as will be explained.

In the region A the bristles 60 and vanes 62 extend radially, but on the opposite side of the rotor the bristles and vanes are progressively bent backwards by engagement with an inwardly curving wall portion 64. These bent bristles are supplied and dampened with water by a wicking action, and when the bristles approach the region A they are suddenly released and spring out to their normal straight radial positions. This sudden outward flicking of the multitudes of dampened bristles as the rotor turns continuously hurls large numbers of tiny droplets of water into the gas mixture. These numerous fine droplets provide a large effective total surface area from which evaporation occurs, thus humidifying the gas mixture. Moreover, many of these droplets are so fine as to remain gas borne and thus continually dampen all of the interior surfaces downstream from the humidifying apparatus.

In order to feed moisture up to the bristles 60 there are a plurality of parallel closely spaced glass plates 66 having their upper ends ground into a saddle configuration at 68. The wicking action of the narrow capillary spaces 69 between the plates 66 draws water up to the saddle surface 68, thus wetting the ends of the bristles as they revolve past the saddle surface 68. At the lip or edge 70 of this saddle surface 68 the bristles 60 and vanes 62 are released and flick out to their normal radial positions, so as to spray the thousands of fine droplets mentioned above.

The propulsive torque for turning the rotor 54 is provided by the gas pressure pushing in a counter-clockwise direction against the fully extended vanes in the region B where these vanes initially engage the wall 64, while the passage 71 to the gas outlet port 58 is adjacent to the ends of the bent vanes as indicated by the dotted outline 58 in FIG. 3. Consequently, the gas flows around the rotor from A to the outlet port 58 and causes the rotor to turn because of the differential in effective area of the straight and bent vanes being acted upon by the gas pressure.

The gas passes inwardly through numerous small openings 72 in the hollow rotor 54 and inwardly through a slot 74 in an inner stationary sleeve 76. A resilient wiper 78 attached to the sleeve 76 on each side of the slot 74 slidingly engages the inner surface of the rotor 54 and causes the humidified gas to follow along the passage as indicated by the arrow 71 and to pass inwardly through the small openings 72 in the vicinity of the slot 74. As shown in FIG. 4, the stationary sleeve 76 is closed at the end near the bearing 56, and this sleeve is attached to the rotor casing by means of a plurality of spaced supports 80 near the outlet port 58.

In addition to the advantageous elimination of the hazard of static electrical discharge, the high humidification of the explosive mixture stabilizes the gas mixture against a tendency to self-induced explosion as a result of the powerful oxidizing activity potential of the oxygen mixed with the combustible gas. Any oxidation process which occurs caused a localized heating in the vicinity of the oxidation, which in turn augments the rate of oxidation causing an upward acceleration of localized heating which could lead to explosion. However, the high water vapor content tends to nullify this instability. A relative humidity above 60 percent as attained with the apparatus of this invention greatly reduces the hazard of accidental explosion of oxygen and combustible gas mixtures, and in most instances this invention enables a relative humidity above 80 percent to be achieved. This higher relative humidity is even more advantageous for reducing the hazards of accidental explosion as discussed above. Also this gh relative humidity inhibits the formation of peroxides and thus increases the stability of the gas mixture.

In this example the rotor 54 is self-driven by the gas mixture; however, it will be appreciated that other safe propulsive arrangements be utilized. For example, a gasdriven turbine or positive-displacement pump drive means can be located in the line 16 or 26, at a position where each gas is pure and hence is non-explosive. Then, this drive means is connected to the rotor 54 so as to turn it and flip the bristles. When external drive means are utilized, the vanes 62 may be omitted if desired. Moreover, clumps and rows of bristles can be arranged on the rotor so as to provide virtual vanes instead of including actual vanes. Hence, as utilized herein the term vane is intended to mean a gas-barrier member for driving a rotor regardless of whether the member is integral or provided by closely spaced parts providing an effective barrier.

It is to be noted that the present invention provides several advantages in its humidifying action. By virtue of the fact that each of the bristles individually is caused to flick, numerous droplets are created and the rotor 54 may be rotated at a relatively low speed. It is pointed out that each flicking bristle is traveling along an arc as it swings to its normal extended position and so the multitudes of fine droplets are thrown centrifugally by the bristles. Also, the individual bristles are arranged by staggering them so that each one individually is flicked rather than having a group of bristles flick as a unit. It will be appreciated that this individual flicking movement of the bristles can be produced by oscillating or vibrating the bristle support at high frequency.

The bristles 60 are moistened by the capillary, liquid supply means 68, but they are not completely immersed in water before their flicking movement. The reason for this is that the most efficient humidifying action is produced by finer droplets created by moistened bristles, whereas bristles which are immersed in water have an excess of Water and do not produce the large number of fine droplets as desired.

It will be appreciated that the various parts are constructed of suitable inert materials with respect to the gases being handled and which can be sterilized by appropriate Well-known hospital techniques. For example, the bristles and vanes are made of a suitable inert flexible plastic material, such as nylon, polytetrafluoroethylene, and the like.

As illustrated in FIG. 5, rapidly moving bristles 82 wet with a desired liquid and driven by suitable motive means 84 produce large numbers of tiny droplets 86. The liquid is supplied from a source 88, for example such as a damp pad or sponge, and the tiny droplets 86 are particularly well adapted for humidifying explosive gas mixtures as described above, but the reader will appreciate that the tiny droplets 86 which are so created are advantageous for a wide variety of uses and applications.

From the foregoing it will be understood that the embodiments of the present invention described above are well-suited to provide the advantages set forth, and since many possible embodiments may be made of the various features of this invention and as the method and apparatus herein described may be varied in various parts, all without departing from the scope of the invention, it is to be understood that all matter hereinbefore set forth or shown in the accompanying drawings is to be interpreted as illustrative and not in a limiting sense and that in certain instances, some of the features of the invention may be used without a corresponding use of other features, all without departing from the scope of the invention.

What is claimed is:

1. In a self-contained system for administering a humid gaseous anesthetic having a desired predetermined humidity independent of ambient atmospheric conditions, the system including a self-contained source of anesthetic, a self-contained source of dry gaseous compressed oxygen and mixing means closed to the ambient atmosphere for receiving the anesthetic and the dry gaseous oxygen from the respective sources and mixing desired proportions of the anesthetic and the dry gaseous oxygen to produce a dry gaseous anesthetic mixture of desired dryness, the improvement comprising:

a casing closed to the ambient atmosphere;

means for introducing the gaseous mixture of anesthetic and oxygen into said casing to establish an atmosphere of desired dryness within the casing; support means;

a plurality of flexible bristle elements carried by said support means, each bristle element projecting from a root portion fixed in said support means to a free p;

a source of liquid;

means for wetting the bristle elements at the tips thereof with said liquid;

means for flexing the bristle elements; and

means for imparting relative motion between the tips of said bristle elements and said means for flexing to flex and suddenly release the flexed bristle elements having wetted tips;

said casing, said support means, said means for wetting,

said means for flexing and said means for imparting relative motion cooperating with one another and with the atmosphere of predictable dryness in the casing such that the sudden release of the wetted bristle tips will generate a multiplicity of fine liquid droplets in the dry gaseous anesthetic mixture enclosed Within the casing and sufiicient predetermined vaporization of the droplets will be accomplished as a result of the desired dryness of the gaseous anesthetic mixture to enable the moistening of said gaseous anesthetic mixture to said desired humidity independent of ambient atmospheric conditions.

2. The combination of claim 1 wherein the means for imparting relative motion between the tips of the bristle elements and the means for flexing includes a gas-driven fluid motor capable of operation by the compressed gas in the system to move the support means and the bristle elements thereon with respect to the means for flexing.

3. The combination of claim 2 wherein said support means comprises a hollow perforated cylindrical rotor and said gas-driven fluid motor includes means for mounting said rotor for rotation eccentrically within the casing such that at least some bristle elements are always urged against at least a portion of the casing as the rotor rotates, and

means for passing the gaseous mixture into the casing,

through the perforated cylindrical rotor, and thence out of the casing such that the bristle members which are urged against the casing serve as vane means for effecting propulsion of said rotor in response to the flow of gas into the casing, through the rotor and out of the casing.

4. The combination of claim 3 including supplementary vane members mounted upon the rotor and projecting toward the casing for further effecting said propulsion.

5. The combination of claim 1 wherein said means for wetting the bristle elements at the tips thereof and the means for flexing the bristle elements having wetted tips include:

a wetted surface so located with respect to said support means and the bristle elements carried thereby that upon relative movement between the tips of said bristle elements and said flexing means, the tips of said bristle elements will contact said wetted surface and said bristle elements will be flexed by the wetted surface and upon movement of the tips of said bristle elements beyond said wetted surface said bristle elements will be suddenly released so that said tips will generate said multiplicity of fine liquid droplets in the gaseous mixture.

6. The combination of claim 5 wherein said means for wetting and flexing the bristle elements comprise capillary feed means disposed in said source of liquid and feeding liquid from said source to said wetted surf-ace.

7. The combination of claim 6 wherein said capillary feed means comprises a plurality of closely spaced plate members.

8. A method of humidifying a gaseous anesthetic mixture to a desired predetermined humidity independent of ambient atmospheric conditions, the gaseous anesthetic mixture being obtained from a self-contained source of anesthetic and a self-contained source of dry gaseous oxygen, the humidity being obtained from a source of liquid and the method being carried out in a casing having an interior closed to the ambient atmosphere with a plurality of flexible bristle elements having free tips movable within the interior of the casing, said method comprising:

mixing desired proportions of the anesthetic and the dry gaseous oxygen outside of the ambient atmosphere to produce a dry gaseous anesthetic mixture of desired dryness isolated from said ambient atmosphere;

conducting the dry gaseous anesthetic mixture into the interior of the chamber;

wetting the bristle elements at the tips thereof with said liquid; and

flexing and releasing the flexed bristle elements having wetted tips within the interior of the casing to generate a multiplicity of fine liquid droplets in the dry gaseous anesthetic mixture isolated from the ambient atmosphere in the interior of the casing thereby accomplishing sufiicient predetermined vaporization of the droplets as a result of the desired dryness of the gaseous anesthetic mixture and enabling the humidification of said gaseous anesthetic mixture to said desired humidity independent of ambient atmospheric conditions.

References Cited UNITED STATES PATENTS HARRY B. THORNTON, Primary Examiner.

E. H. RENNER, Assistant Examiner. 

1. IN A SELF-CONTAINED SYSTEM FOR ADMINISTERING A HUMID GASEOUS ANESTHETIC HAVING A DESIRED PREDETERMINED HUMIDITY INDEPENDENT OF AMBIENT ATMOSPHERIC CONDITIONS, THE SYSTEM INCLUDING A SELF-CONTAINED SOURCE OF ANESTHETIC, A SELF-CONTAINED SOURCE OF DRY GASEOUS COMPRESSED OXYGEN AND MIXING MEANS CLOSED TO THE AMBIENT ATMOSPHERE FOR RECEIVING THE ANESTHETIC AND THE DRY GASEOUS OXYGEN FROM THE RESPECTIVE SOURCES AND MIXING DESIRED PROPORTIONS OF THE ANESTHETIC AND THE DRY GASEOUS OXYGEN TO PRODUCE A DRY GASEOUS ANESTHETIC MIXTURE OF DESIRED DRYNESS, THE IMPROVDMENT COMPRISING: A CASING CLOSED TO THE AMBIENT ATMOSPHERE; MEANS FOR INTRODUCING THE GASEOUS MIXTURE OF ANESTHETIC AND OXYGEN INTO SAID CASING TO ESTABLISH AN ATMOSPHERE OF DESIRED DRYNESS WITHIN THE CASING; SUPPORT MEANS; A PLURALITY OF FLEXIBLE BRISTLE ELEMENTS CARRIED BY SAID SUPPORT MEANS, EACH BRISTLE ELEMENT PROJECTING FROM A ROOT PORTION FIXED IN SAID SUPPORT MEANS TO A FREE TIP; A SOURCE OF LIQUID; MEANS FOR WETTING THE BRISTLE ELEMENTS AT THE TIPS THEREOF WITH SAID LIQUID; MEANS FOR FLEXING THE BRISTLE ELEMENTS; AND MEANS FOR IMPARTING RELATIVE MOTION BETWEEN THE TIPS OF SAID BRISTLE ELEMENTS AND SAID MEANS FOR FLEXING TO FLEX AND SUDDENLY RELEASE THE FLEXED BRISTLE ELEMENTS HAVING WETTED TIPS; SAID CASING, SAID SUPPORT MEANS, SAID MEANS FOR WETTING, SAID MEANS FOR FLEXING AND SAID MEANS FOR IMPARTING RELATIVE MOTION COOPERATING WITH ONE ANOTHER AND WITH THE ATMOSPHERE OF PREDICTABLE DRYNESS IN THE CASING SUCH THAT THE SUDDEN RELEASE OF THE WETTED BRISTLE TIPS WILL GENERATE A MULTIPLICITY OF FINE LIQUID DROPLETS IN THE DRY GASEOUS ANESTHETIC MIXTURE ENCLOSED WITHIN THE CASING AND SUFFICIENT PREDETERMINED VAPORIZATION OF THE DROPLETS WILL BE ACCOMPLISHED AS A RESULT OF THE DESIRED DRYNESS OF THE GASEOUS ANESTHETIC MIXTURE TO ENABLE THE MOISTENING OF SAID GASEOUS ANESTHETIC MIXTURE TO SAID DESIRED HUMIDITY INDEPENDENT OF AMBIENT ATMOSPHERIC CONDITIONS. 